Fluid actuated tool



'June 7 1949- P. VAN slTTERT 2,472,352

FLUID ACTUATED l.TOOL

Filed DSG. 30, 1943 IN VEN TOR.

PAUL l//V J/ TTE'R T `BY Y l Patented June 7, 1949 i1 NITED- STAT asI PAT-ENT or 214124352?) t u FLUID Ao'rUA'r'En 'rioly Paul van Sitten, shaker Heights; ohiajas'sigg; by mesne assigmentsto 'Reed Roller'Bit'Cm# pany, Houstom Tex., a corpbratio'ofTexas Y Application December' 30, 19x43; Serial No.' 516,232"

- 2 Claims.'

The present invention relates broadly toflud actuated tools, but more particularly tothe con# structionof cushioning means vfor the plunger or pistonof such tools.

lAllv important object of the invention is te.

provide. means in the front end. of the barrel. Qi a iiuidactuated tool for cushioning the impacts of the reciprocating piston or p'1unger. 4 Another-object of the invention isto a member in the. form of a. sleeve held in the' front end of the barrel of a uid actuated took. which sleeve receives a portion of the shank of the cutting tool and serves to vtrap air between the forward end of the plunger andthe sleeve, thus forming a cushion for the plunger. Other objects and advantages more or, less, ancillary to the foregoing reside inthe specific construction and aggroupment of the elements. peculiar to. this, structureas willbecorne. apparentA from a more complete examination of this specifi'- cation. l Y y AIn the drawing which illustrates the invention: t 4 Fig. 1 is a. longitudinal sectional view of a iiuidA actuated tool embodyingthe invention; Fig. 2 isy a cross sectional view thereof taken substantially on line 2'-,2 of Fig. 1.

Fig. 3 is a perspective view, ,partlyv in section', of the cushioning. sleeve removed from the tool. Referring to the drawing for .a more detailed description. thereof, a uid actuated tool of the chippinghammer type is generallydesignated by the reference numeral 5 and is shown to include a cylinder 5 having a piston or plunger 'l reoiprocable therein and active on .the shank ,S of. a,` chipping tool I0. To the cylinder 6 is threadedly secured as indicated at ll `a pistol grip. handle l2. Al lock nut andbolt l 3 maintains; the handle in xed positonron ther cylinder but capable. er detachment therefrom. l l n yl l vYNIhe. cylinder 5 serve/.S as. a barrel for' theto'ol andis formed centrally thereotwith a bere (l which i the. piston -1 is movably. actuated. .by air; or other compress'ible uid admitted Within tkiebore in a manner tic. be hereinafter more fullyl described. The, frontend l5 of the barrell has, Iittedthrein a. nose piece I6, the lin terion*diarn-n eter of .which is substantially ,equal to'l the outer di, meter Vci the vshank 9, ivlierebv said shankis `id11y positioned and removed. Urged mit the provide' mart-er mgrejfmly described:

the ring 29,' when initially'insertinvthe sleeve IHS withmunne bore- 14,;- 4is; cjcnrpressedso` as" te be msertabie within the' here ahead ofthe' s e1/e;4 and the ring will maintain its` coiriprefssedl or reduced. shape' and size as vsaidvnslee'v'e` is moved forwardly of the barrel. An' annular groove 2l isk lfci'medwithin they bore L4 adjacent thareai endl of the nose' piece lriri which the ring; 2j' will s'napas" the sleev'e" I8 reaches' thatportion' of thebrle, indicating" to the person' assembling the tool that the sleeve" [8 hajsjaboutreacheditdesiredlcation." Asmore paljticularly shovvnfin) Eig. v1 of ihenrawinjg, the; sgieev'e xa; 1S-rahmenwithl a here" 22 which-1s slightly ia'rger indiani-jj eter thanr the Shanna mwhich isy loosely received the back en'djof' saids'hank, and`V communicating therewith is a second bore 2'3 ofis1ightlyp sma1lf diameter.' T hje endof the sleevejly oppo:siteth annals-r move la tapers outwardly from the; here 23 as` indicated' at 23a for a purpose to' be here# The handle l2 is provided with passage which coxnniju`r1i-ca te1s'"v with; a' valve controlled inlet' passagegzs' 1ad11n'g'-irommtne pipe conne" tionl in1 whichjma'y be s'Yecurg'gt-1,the,end` of a muv@ nur@ .supplying conduit (not shown pipepconnectionz' is thrzeadedlysecured Within abushing 2l which is in turn removably conf ne'cted by means of thethre'ad'sl 21 to the "end or l,the handle. mTl'ielovvefr endf` of the passage 2l' communicates wana bore 25s mme m mamada? (2 atan @pgntothe inierpassage g5. @pas j ing 29 is screwed; Within thefbor 2.8' and stringi." Ofn' its unifier. end?) Dil@ f Washer-likemembers @which "Verve, asia seat' for the.I valve 3 I. wlie vat/e315. yhad;,assunti,its seat, by ar spring; az'rupj; ported. wenn, the nushmebvm instar. .nut 3,3.; valve 3l normally in engagementwith its seat.. 3,02. f cr prevenung'the admission of" motiv fiuillfrcmthe passes 25 thfl'ihl .th p Sgll mm' the bore M to2 ect r'eciprpjction ofi t f plunger 1j. Extending u mrarclly,froml the v y 3151's, a4 icabi ,in a pusiding.n as maratea 3 slot 31 by a cross pin 38. A second cross pin 39 is also provided in the slot 31 which guides the lever 36 thro'ugh the arcuate shaped slot 40.

In the assembly of the tool a valve block 4| is positioned adjacent the back end of the barrel 6 which cooperates with the valve block button 42 for controlling the admission of motive fluid into the bore I4. The valve block button 42 is formed with a passage 43 which communicates with a passage 44 formed in the valve block 4I, the latter passage being controlled by means of a disk valve 45 held within an annular groove 46 between the valve block and button 4| and 42, respectively. The disk valve 45 controls the admission of motive fluid into the bore I4 through the passage 41. The valve block and button are formed with a continuous passage 48 which communicates with a passage 49 formed in the wall of the cylinder 6 which passage communicates with the front end of the bore I4 through a port 50 preferably spaced a short distance from the front end of the .cylinder or the rear end of the member I8. Air from the bore I4 is exhausted through the port and passage 52, the latter communicating through the port 53 with an annular chamber 54 which surrounds the valve block and button 4|. and 42. From the annular chamber 54 the fluid is exhausted through the ports 55 concealed by means of a deflecting ring 56. The valve block button 42 is formed with a passage 51 which communicates with the annular groove 46 controlled by the disk valve 45.

. In the operation of the device, when desiring to operate the tool, the lever 36 is swung on its pivot 38 to depress the pin 34 to unseat the valve 3|. Motive fluid is then free to ow through the passage 24 from the .passage 25 where it is admitted through the passages 43 :and 44 forcing the valve 45 toward the valve block button and permitting the uid to enter the bore I4 through the passage 41. The admitted fluid moves the piston 1 Itoward the forward end of the tool moving the reduced end 58 thereof through the restricted bore 23 into contact with the end of the shank 9. As the plunger 1 moves forwardly inthe barrel, it uncovers the exhaust port `59, allowing iluid in back of the piston to be exhausted through said port by means of the passage 52, port 53, chamber 54, and port 55 to atmosphere. This exhausting of the fluid will lower the pressure in the bore to such an extent that fluid entering the passage 51 will move the valve 45 toward the valve block 4|, thereby closing the passage 41 and permitting the uid to move through the passages 48 and 49 and port 5U for reversing the movement of the plunger 1. During that portion of the cycle when the fluid begins to discharge through the port 50, the end 58 of the plunger 1 has entered the restricted bore 23, thus preventing escapement of fluid through the front end of the tool and trapping the fluid between the flared end of the sleeve I8 and the tapered arean of the piston 1. This volume of fluid trapped between the plunger o1 piston and the sleeve I 8 acts as a cushion to prevent abrupt contact of the plunger with the sleeve which would cause injury to one or -both of the parts. As soon as the pressure of the iluid between the forward end of the piston and the sleeve is suicient to overcome the pressure in back of the piston, said pis-ton Awill be moved tow-ard the back of l'the tool uncovering the port 5|, permitting the uid to be exhausted through the passage 52, port 53, chamber 54, an-d outl-et 55, and the tool iszthen ready to repeat the cycle.

'Fluid will be admitted into the bore I4, and the plunger 1 will continue to reciprocate so long as the lever 36 holds the pin 34 down and the valve 3| disengaged from its seat.

From the above description when taken in connection with the accompanying drawing, it will `be readily apparent that a means has been provided in the front end of the barrel of a uid actuated tool which will trap the motive fluid employed for operating the tool whereby said uid will serve as a cushioning agent to prevent injury of the plunger as it impinges the cutting tool. It is also apparent that should the plunger impinge the cutting tool without being cushioned in the manner designed, the cutting tool I 0 would, in all probability, be struck with suilicient force to completely dislodge it from its retaining nose IIS.

Although the foregoing description is necessarily of a detailed character, in order to completely set forth the invention, it is to be understood that the specific terminology is not intended to be restrictive or confining, and it is to lbe further understood that various rearrangements of parts and modifications of structural detail may be resorted to without departing from the scope or spirit of the invention as herein claimed.

I claim:

1. In a tool of the character :described: a housing having a bore extending therethrough, a. handle secured to one end of said housing, a uid actuated plunger reciprocable within said bore formed with an operating tool engaging reduced end portion, a nose piece secured within the other end of said housing adapted to slidably receive the shank of an -operating tool to be impinged by the reduced end portion of said plunger, a sleeve secured in said housing bore adjoining the inner end of said nose piece, said sleeve having a bore therethrough with an enlarged front portion surrounding the end of said shank and a reduced rear portion aiording a sliding 'bearing for the reduced portion of said plunger immediately -before and after impingement of said plunger on said shank, and means for admitting motive fluid alternatively into opposite ends of said housing bore for -actuating said plunger, said means comprising a conduit in said housing terminating in a port adjacent to but spaced from said sleeve and adapted to be closed by said plunger whereby motive iiuid is trapped longitudinally between said plunger and sleeve and laterally between the wall of said housing bore and the front end por tion of said plunger.

2. In a tool of the character described: a. housing having a bore centrally therethrough of a. uniform diameter, a fluid actuated plunger reciprocable within said bore formed with a front end portion of reduced diameter, a nose piece secured within the front end of said housing bore adapted to slidably receive the shank of an operating tool having impacts delivered thereon by the front end portion of said plunger, and a sleeve secured in said housing bore adjoining the inner end of said nose piece, said sleeve having a bore therethrough, which bore is provided with an enlarged front portion surrounding the end of said shank and a reduced portion aiording a sliding bearing for the reduced front end of said plunger during impacts of the plunger on said shank, and means for admitting motive fluid alternatively into opposite ends of said housing bore for actuating said plunger, said means comprising a conduit in said housing terminating in a port adjacent to but spaced Vfrom said sleeve and adapted 5 6 eo be closed by s ai-d plunger whereby motive ud UNITED STATES PATENTS 1s trapped longl-tudmally between said plunger and sleeve `emcl laterally between the Wall of said Number Name Date housing bore and the front end portion of said 482,942 Drawbaugh Sept. 20, 1892 plunger. 5 605,486 Kotten June 14, 1898 1,022,837 French Apr. 9, 1912 PAUL VAN SITTERT. 1,124,627 Leyner Jan, 12, 1915 1,130,957 Bayles Mar. 9, 1915 1,224,089 Hawley Apr. 24, 1917 REFERENCES CITED 10 1,240,708 H-aesler Sept. 18, 1917 The following references are of record in the 1,574,762 Smltll Mal- 2, 1926 il@ of this patent: 1,589,295 JlmBI'SOn June 15, 1926 1,968,376 Curtis July 31, 1934 

